JaLCDOI 10.18926/15462
FullText URL Mem_Fac_Eng_OU_23_1_39.pdf
Author Osaka, Akiyoshi| Yuasa Motokazu| Miura, Yoshinari| Takahashi, Katsuaki|
Abstract Sodium borosilicate gels of compositions similar to that of Vycor(R) glass like 80SiO(2).15B(2)O(3).5Na(2)O (wt%) were prepared from hydrolysis and polycondensation of metal alkoxides under the HCl catalysis. Variation of specific surface area and porosity with temperature indicated that closed pores were opened below 400℃, and collapsed above 450℃ after the porosity reached a maximum value around 450℃. The structural evolution was examined due to IR spectra and a phase separation in the gels was observed. The solubility of the gels into 1N-HCl was studied as a function of the treatment temperature.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1988-11-22
Volume volume23
Issue issue1
Start Page 39
End Page 48
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307518
JaLCDOI 10.18926/15464
FullText URL Mem_Fac_Eng_OU_28_2_77.pdf
Author Osaka, Akiyoshi| Kawamura Haruyuki| Miura, Yoshinari|
Abstract Amorphous films of lead oxyfluorosilicate were prepared with a rf-sputtering technique, and the distribution profiles of the component elements and chemical states of the fluoride ions were analyzed with an X-ray photoelectron spectrometer. Si atoms with an expanded coordination, O(4)Si-F, were present near the surface, and O(3)Si-F units were present in the deeper part of the films. Electrical resistance indicated transition to a conduction state for the films containing fluoride ions, while the films were crystallized to precipitate low quartz by the irradiation of He-Ne laser of 3 mW up to 1 sec.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1994-03-15
Volume volume28
Issue issue2
Start Page 77
End Page 84
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307766
JaLCDOI 10.18926/15473
FullText URL Mem_Fac_Eng_OU_26_2_61.pdf
Author Osaka, Akiyoshi| Kawabata Kouji| Nanba, Tokuro| Takada, Jun| Miura, Yoshinari|
Abstract Mullite-dispersed silica ceramics were prepared through sol-gel processing by the use of tetraethoxy silane, aluminium nitrate and aluminium isopropoxide as the Si and Al sources where HCl and HN0(3) were the catalyst. Effect of the starting materials, solvents and catalysts was examined on the gelation time or temperature of mullite precipitation. Apparent activation energy of gelation ranged from 80 to 95kJ/mol. The presence of AI in the sols elongated the gelling time suggesting the formation of chelate bonds between AI and Si-OR or Si-OH bonds.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1992-03-28
Volume volume26
Issue issue2
Start Page 61
End Page 67
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307416
JaLCDOI 10.18926/15474
FullText URL Mem_Fac_Eng_OU_24_1_53.pdf
Author Osaka, Akiyoshi| Takao Seiji| Oda, Kiichi| Takada, Jun| Miura, Yoshinari|
Abstract Electrical resistance and X-ray photoelectron depth profile analysis are studied for antimony doped tin oxide films developed on silica, alkali-free and sodalime slide glass substrates. The sodium ions diffused from the substrates to the films prevented the crystal growth of rutile type tin oxide in the film, resulting in the high electrical resistance. A diffusion layer has been detected for each film with diffuse profiles of multi valent cations (Sn, Si or Ca) at the interface of the tin oxide film and substrate. A greater amount of sodium atoms have been detected in the film developed on the soda-lime glass while almost no sodium atoms have been found in those on the other substrates. This can be explained by the diffusion of the sodium ions in the substrate due to a drastic hydronium-sodium exchange mechanism under highly acidic conditions during the dipping and drying processes.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1989-11-29
Volume volume24
Issue issue1
Start Page 53
End Page 61
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307279
JaLCDOI 10.18926/15486
FullText URL Mem_Fac_Eng_OU_25_1_23.pdf
Author Miura, Yoshinari| Takada, Jun| Osaka, Akiyoshi| Kawamura, Toshio|
Abstract Zinc oxide films were prepared on silica glass substrates by the use of an r.f. activated reactive evaporation (ARE) method, and were examined by X-ray diffraction (XRD) and scanning electron micrograph (SEM). XRD measurements indicate that the films were c-axis oriented and that an r.f. plasma of Zn and O was necessary for the ZnO film deposition. Substrate temperature, oxygen gas pressure, evaporation rate, r.f. power and inlet position of oxygen gas effect the c-axis orientation, the growth rate and the microstructure of the films. Optimum conditions for a dense film with a fine texture of the surface and having good crystallinity were as follows: the substrate temperature;400℃, the evaporation rate;5.0(A)/s, the oxygen pressure;2.0x10(-4) Torr, the r.f. power;150 to 200W, and the oxygen gas inlet near the substrate. For the film prepared under the optimum conditions, the standard deviation σ of the rocking curve for the (002) diffraction was 1.9deg, smaller than that of the film prepared by using an r.f. sputtering method.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1990-12-14
Volume volume25
Issue issue1
Start Page 23
End Page 35
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307600
JaLCDOI 10.18926/48126
FullText URL mfe_046_010_020.pdf
Author Kanatani, Kenichi|
Abstract We present a new technique for calibrating ultra-wide fisheye lens cameras by imposing the constraint that collinear points be rectified to be collinear, parallel lines to be parallel, and orthogonal lines to be orthogonal. Exploiting the fact that line fitting reduces to an eigenvalue problem, we do a rigorous perturbation analysis to obtain a Levenberg-Marquardt procedure for the optimization. Doing experiments, we point out that spurious solutions exist if collinearity and parallelism alone are imposed. Our technique has many desirable properties. For example, no metric information is required about the reference pattern or the camera position, and separate stripe patterns can be displayed on a video screen to generate a virtual grid, eliminating the grid point extraction processing.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 2012-01
Volume volume46
Start Page 10
End Page 20
ISSN 1349-6115
language 英語
Copyright Holders Copyright © by the authors
File Version publisher
NAID 80022451621
JaLCDOI 10.18926/15398
FullText URL Mem_Fac_Eng_OU_27_1_93.pdf
Author Nishigaki, Makoto| Sudinda Teddy| Hishiya Tomoyuki| Kohno, Ichiro|
Abstract In this paper the author will be describe phenomena of advection dispersion in subsurface flow by using Eulerian Lagrangian Finite Element Method. Where Finite Element Method with Galerkin formulation and weigthed residual method is used to solve seepage and advection dispersion equation. The problem of one dimensional and two dimensional rectangular wave are analyzed in this paper. And the result of numerical analyses will be compared with analytical solutions. The numerical results showed the very good agreement with the analytical solutions.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1992-11-25
Volume volume27
Issue issue1
Start Page 93
End Page 105
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307768
JaLCDOI 10.18926/15440
FullText URL Mem_Fac_Eng_OU_28_1_71.pdf
Author Nishigaki, Makoto| Sudinda Teddy| Hishiya Tomoyuki| Kohno, Iichiro|
Abstract In this paper, method of Eulerian Lagrangian numerical analysis is used to described Advection-Dispersion phenomena. The influence of concentration to the density of fluid is considered. A laboratory model of a two dimensional confined aquifer containing an isotropic, homogeneous porous medium (Hosokawa et.al 1989) was used to validate the applicability of Advection-Dispersion of numerical analysis with steady and unsteady state condition [1].
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1993-11-30
Volume volume28
Issue issue1
Start Page 71
End Page 85
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307975
JaLCDOI 10.18926/15442
FullText URL Mem_Fac_Eng_OU_28_1_87.pdf
Author Motojima Isao| Kono, Iichiro| Nishigaki, Makoto|
Abstract In recent years, construction or planning of large-scale underground structures, such as underground power plants, underground oil storage plants and nuclear power plants have been coming into consideration in Japan. To construct such as large-scale underground structures, one of the most important problems is to make clear beforehand the behavior of groundwater around these structures and the other is to carry out proper countermeasure of groundwater, so that these structures can be constructed safely and maintained stability over a long time period. This report describes the results of theoretical studies on the drain systems and at the same time, discusses the drain systems around the underground cavern for the practical underground power stations.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1993-11-30
Volume volume28
Issue issue1
Start Page 87
End Page 128
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307220
JaLCDOI 10.18926/15463
FullText URL Mem_Fac_Eng_OU_28_2_59.pdf
Author Nishigaki, Makoto| Sun Yao| Kohno, Iichiro|
Abstract In this paper, first, an elasto-plastic consitituve equation for unsaturated soil was developed by considering of the basically behavior of unsaturated soil. Second, the results of a number of triaxial test and a set of rigid foundation model tests were simulated by using this constitutive equation, the agreement between observed and computed results was satisfactory and confirms the possibilities of this constitutive equation.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1994-03-15
Volume volume28
Issue issue2
Start Page 59
End Page 75
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307850
JaLCDOI 10.18926/15492
FullText URL Mem_Fac_Eng_OU_25_1_59.pdf
Author Kohno, Iichiro| Nishigaki, Makoto| Okada Junji|
Abstract In this paper, we propose a method to determine the coefficients of permeability of the unconfined aquifer consisted of two different permeability layers. With mixing the conventional pumping test and falling head permeability test, the coefficients of permeabilitiy k(1) and k(2) were obtained. The validity of the proposed method is investigated by using the numerical simulation. As the results, it becomes apparent that the proposed method is applicable to real hydarulic problems.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1990-12-14
Volume volume25
Issue issue1
Start Page 59
End Page 69
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307472
JaLCDOI 10.18926/15393
FullText URL Mem_Fac_Eng_OU_30_2_15.pdf
Author Oka, Hisao| Fujiwara, Shiro|
Abstract An estimation of muscle fatigue is very important study and many laboratory researchers had done actively in this field. The excellent measurement and analysis methods, however, have not established yet. The aim of this study was to investigate the muscle fatigue of low back, caused by sitting on the vehicle seat for a long time. The muscle viscoelasticity and the EMG (Electromyogram) were measured. The authors proposed the objective muscle fatigue index that was obtained from the result of PCA (Principal Component Analysis) by using the measured varlables. The objective muscle fatigue index suggests an adequate correlation with the subjective fatigue on the vehicle seat.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1996-03-29
Volume volume30
Issue issue2
Start Page 15
End Page 20
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307965
JaLCDOI 10.18926/15400
FullText URL Mem_Fac_Eng_OU_27_2_11.pdf
Author Oka, Hisao| Yamamoto, Tatsuma| Saratani Keiji| Tanaka Masahiro| Kawazoe Takayoshi|
Abstract The use of dental implants has increased together with increases in the human life span and it has become an imperative subject for dentists to familiarize themselves with this treatment modality. Unfortunately, there has been no practical and quantitative method for in vivo evaluation of the stability of dental implants. In the tooth mobility examination, the tactile sense of natural teeth is different from that of dental implants. The authors have developed an automatic diagnosis system of tooth mobility for clinical use. The biomechanical mobility of peri-implantium is measured with a pseudo-random vibration, from which the viscoelasticity c1, c2, k of peri-implantium is obtained. The diagnosis system has been applied to the quantitative evaluation of the stability of implants : endodontics endosseous implants (titanium pin), endosseous implants (Bioceram). It has also been applied to the evaluation of the long-term prognoses of dental implantation (Bioceram) and the examination of Intramobile implant (IMZ), and the satisfactory results have been obtained.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1993-03-25
Volume volume27
Issue issue2
Start Page 11
End Page 17
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002308018
JaLCDOI 10.18926/15415
FullText URL Mem_Fac_Eng_OU_29_2_29.pdf
Author Oka, Hisao| Fukuda, Takashi|
Abstract In the stiffness evaluation from the skin surface, the body structure under the skin, like a bone and muscle, influences on the measurement results. The authors developed the measurement system of biomechanical impedance with applying a vibration of acoustic frequency onto the body surface. We measured the viscoelasticity of the silicone-gel model, which involves metal blocks, from the gel surface by using this system. The internal structure of model is estimated from the relation between the viscoelasticity and the distance from the gel surface to the internal block. Applying this method, the shape of ribs of the right chest are estimated. The shapes and viscoelasticity of silicone-gel tumor model, which has two different tumors, are also estimated.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1995-03-27
Volume volume29
Issue issue2
Start Page 29
End Page 37
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307199
JaLCDOI 10.18926/15416
FullText URL Mem_Fac_Eng_OU_26_1_43.pdf
Author Bouzidi, Moncef| Koga, Ryuji| Wada, Osami| Kagawa, Naoki| Hai Xu| Kosaka, Megumi| Sano HIroya|
Abstract A numerical technique called as "adjoint spectrum" has been proposed by the authors in a previous work. Two applications of it are presented here. It is demonstrated that by generalizing the aspect of adjoint spectrum it becomes possible to measure densities of mixed gases simultaneously. An experimental proof of this has been carried on and simultaneous measurement of densities of both methane and dinitrogen oxide was realized. On the other hand, it is also reported that frequency shifting of spectra, which is a cause of error in spectrometric measurements, can be corrected by exploiting the adjoint spectrum technique in connection with the Taylor expansion. Numerical examples showing the success of this method are reported as well.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1991-11-30
Volume volume26
Issue issue1
Start Page 43
End Page 49
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307796
JaLCDOI 10.18926/15417
FullText URL Mem_Fac_Eng_OU_29_2_39.pdf
Author Oka, Hisao| Sakamoto, Shun-ya| Irie Takashi|
Abstract The body structures under the skin surface, such as bones and tendon, have an influence on the stiffness evaluation observed from the surface. In this case, the observed stiffness should be called an apparent stiffness. To obtain the biomechanical properties of skin itself, the influence of body structure should be removed. This study deals with the correction method of apparent viscoelasticity which calculated from apparent biomechanical impedance. This method is applied to the measured result of the forearm and the right chest to confirm its effectiveness.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1995-03-27
Volume volume29
Issue issue2
Start Page 39
End Page 47
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307527
JaLCDOI 10.18926/15446
FullText URL Mem_Fac_Eng_OU_22_1.pdf
Author Oka, Hisao| Yamamoto, Tatsuma|
Abstract Biomechanical impedance is relatively small compared to industrial mechanical impedance. Thus it is difficult to measure it precisely. A biomechanical impedance measuring system was developed for portable use by means of random excitation. This system doesn't require a fixed body and vibrator supporting apparatus. In order to obtain an impedance spectrum, the FFT processing is performed using a personal computer. The spectra of the biomechanical impedance which is measured on body surfaces depend on body positions and can be roughly classified into three spectra patterns : soft, stiff and intermediate. During the measurement, the measuring conditions (preload, diameter of the vibrating tip etc.) influence the results. However, it became clear that the linearity of the biomechanical impedance was satisfied in the limited measuring conditions. Accordingly it is possible to standardize the impedance and to compare it with the results under different measuring conditions.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1988-03-31
Volume volume22
Start Page 1
End Page 14
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307480
JaLCDOI 10.18926/15465
FullText URL Mem_Fac_Eng_OU_23_1_49.pdf
Author Oka, Hisao| Yamamoto, Tatsuma| Isayama Yoshiharu|
Abstract In the field of dental study it is most fundamental and necessary to estimate the condition of periodontium. In order to examine a mechanical characteristics of periodontium, the theoretical displacement response to periodontal mechanical model (three elements model) are strictly solved in case of some pulse excitations. Impact excitations (rectangular, triangular and half-cycle sine pulse) are given in physical and mathematical definitions and complete solutions to the impact excitations are provided. The triangular pulse excitation which is obtained by means of a fracture of pencil-lead is most suitable. The mechanical parameters of periodontium are given using this input excitation. This is experimentally confirmed by artificial tooth model. The obtained mechanical characteristic of the periodontal tissues can be applied to clinical diagnosis.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1988-11-22
Volume volume23
Issue issue1
Start Page 49
End Page 60
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307622
JaLCDOI 10.18926/15476
FullText URL Mem_Fac_Eng_OU_24_1_63.pdf
Author Yamamoto, Yoshitake| Isshiki Hiromi| Oka, Hisao| Yamamoto, Tatsuma|
Abstract There is no doubt that many people feel the peace of mind or the pleasures of senses in appreciating music. But the estimation of the effect is very difficult and the objective estimation can be hardly done. This study proposed the objective estimating method of human emotion utilizing galvanic skin reflex (GSR) which reflects a human psychological activity. In this method, not by individual response, but by the series of response and pattern of appearance of GSR, the emotional response under appreciating music was investigated. In the case of appreciation of the same classic music to several subjects, the individual GSR responses are random and remarkable characteristic could not be find on the results. However, on the patterns of appearance of GSR, the patterns obtaining from the same generation are much similar each other and the patterns obtaining from different generation are less similar. It was cleared that the same music gave different effect on different generations.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1989-11-29
Volume volume24
Issue issue1
Start Page 63
End Page 72
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307670
JaLCDOI 10.18926/15479
FullText URL Mem_Fac_Eng_OU_24_1_73.pdf
Author Oka, Hisao| Isayama Yoshiharu| Yamamoto, Yoshitake| Yamamoto, Tatsuma|
Abstract There is a small vibration which goes undetected by the naked eyes. It is called a microvibration (MV) or a minor tremor (MT). The MV on the body surface is expected to apply to a clinical examination of the autonomic nervous system. It is not cleared why and how the MV occurs, but there are many papers about its occurrence and clinical application. In this study, MV measuring system, its estimation and basic characteristics are examined. The difference between head MV and thenar MV, individual MV and diurnal and seasonal change are discussed. The power spectrum of MV is obtained using an autoregressive model.
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Published Date 1989-11-29
Volume volume24
Issue issue1
Start Page 73
End Page 80
ISSN 0475-0071
language 英語
File Version publisher
NAID 120002307633